Major depression affects roughly one in 15 Americans. Yet this common mental disorder is frequently misunderstood. Because we value traits like happiness and energy, depression is sometimes incorrectly viewed as sadness, laziness, or even selfishness—even by those who may be suffering from it.

That’s too bad, because today’s treatments for depression are more effective and precisely targeted than ever.

To tell whether you may have major depression, or have had it in the past, try this simple quiz:

Over a two-week period, have you felt “down” or uninterested in your usual activities—for most of the time, on most days?

If you can honestly answer no to this question, then you probably won’t be diagnosed with major depression. But you should know that having some symptoms of major depression may be a sign of disorders that are also serious and treatable. See Part Three for more info.

Take a look through the list of symptoms below:

If you’ve experienced four or more of these symptoms—on most days, over those same two weeks we talked about in Part One—you may have major depression. And you should speak soon to someone who can help, especially if thoughts of suicide made your list.

If you have some of the symptoms above, but not enough for a diagnosis of major depression, you may have another treatable form of depression, such as:

Whatever your symptoms of mind or mood, suffering in silence doesn’t help. Talk to your doctor or a mental health professional. They’ll have solutions and strategies that can get you feeling like yourself again.